Flood barriers are increasingly used as cofferdams, mostly driven by flexibility, lower costs and environmental protection, such as silt control and plant disturbance.
On the south coast of NSW the BoxBarrier mobile flood barrier was used as a cofferdam whilst the Soil Conservation Service of NSW completed work on a road that crossed over a high priority mangrove rehabilitation area.
A new culvert under the road improves the flow of tidal water upstream, expanding the area where mangroves can re-grow.
The salt water was no problem for the BoxBarriers.
The deployment into the already flooded area was no problem.
The mud was not a problem for the barriers, but a muddy challenge for those deploying the cofferdam.
Instead of removing the mangroves that had grown in the past 12 months, the scope was to work around them and if needed, to deploy the barriers on top of them.
The mangroves indeed bounced back after the cofferdam was removed a few days later.